Midway through last month, when the Occupy movement was at its peak and the New York police department was keeping its distance from Zuccotti Park, I was in Berkeley, California. Outside a branch of Bank of America, a compact local Occupy camp had sprung up, apparently drawing on a mixture of battle-scarred lefties, students from the University of California, and the sizeable local homeless population. Their line of argument was captured on A4 flyers that were pasted on to every available surface in the surrounding streets, the most direct of which read thus: "Are you pissed [off] yet? You should be! No taxation of the rich. Endless war. Bankers not held responsible. Corrupt politicians. Destruction of the planet due to politicians' and corporations' greed. Can it get any worse than this?"

On a trestle table lay small piles of a leaflet credited to the "Bureau of Public Secrets", which quoted 69-year-old Kalle Lasn, the editor of the Canada-based countercultural magazine Adbusters: "We are not just inspired by what happened in the Arab spring recently. We are students of the situationist movement. Those are the people who gave birth to what many people think was the first global revolution back in 1968 when some uprisings in Paris suddenly inspired uprisings all over the world."

Looking at the shabby camp in front of me, any talk of Paris in 1968 seemed absurd – but then again, subsequent events in nearby Oakland, where thousands of Occupy supporters took to the streets on 3 November maybe suggested that such reference points were not completely misplaced. The 1968 reference also chimed with an article, not from any anarchist leaflet, but from the Financial Times, titled 2011: The Year of Global Indignation, and written by the paper's foreign affairs columnist, Gideon Rachman. "Many of the revolts of 2011 pit an internationally connected elite against ordinary citizens who feel excluded from the benefits of economic growth, and angered by corruption," he wrote. "The creation of a global mood is a mysterious thing. In 1968, before the word 'globalisation' or the internet were even invented, there were student rebellions around the world. The year 1989 saw not just the fall of the Berlin Wall but the Tiananmen Square revolt in China." And then a tentative question: "Perhaps 2011 will come to rank alongside 1968 and 1989 as a year of global revolt?"

This year has so far seen convulsive events in Tunisia, Egypt, Libya, Bahrain, Syria and Yemen. Mass protests against economic breakdown and austerity in Greece, Italy and Spain. Marches and protest camps in Chile and Israel. The arrival of Occupy Wall Street – which was cleared by police yesterday, though it will surely return in some form – and a movement-cum-meme which quickly arrived in London and beyond. And all the time, from Arab dictatorships, through to the world's banks and the Murdoch empire and now the vast edifice of the EU, the sense that interests and institutions, that once seemed invincible are either cracking or being questioned as never before, while mainstream politics is left looking bereft not just of answers, but even ideas.

But what connects the crowds who are making all the noise? What could link a student camped outside St Paul's to Mohamed Bouazizi, the Tunisian vegetable seller who, having set himself on fire, died on 4 January, and thereby set in motion the events we now know as the Arab spring? How to draw lines from the Spanish indignados to the student protestors responsible for the so-called Chilean winter?

Sometimes, the answer seems to lie in actual links between the people at the centre of events. On 26 October, for example, Occupy Wall Street was visited by a group of activists drawn together by the Egyptian Facebook-based 6 April movement, who blessed the camp with the spirit of Tahrir Square; a fortnight ago, demonstrators outside St Paul's Cathedral conducted a live video linkup with pro-democracy activists in Syria. Such moments highlight the kind of people who have taken the lead in spreading the message of protest and dissent: a new political breed, unlike their politicised predecessors in some respects; but in others, remarkably similar.

Graduates with no future

"They all looked alike. They would immediately recognise each other. They seemed to possess a silent but absolute knowledge of certain issues, but to be totally ignorant about others. Their hands were unbelievably skilful at pasting up posters, handling paving stones, spraying on walls ... all the while calling for more hands to pass on the message they'd received, but not completely deciphered."

So runs a passage from Chris Marker's documentary A Grin Without a Cat, about the rise and fall of the forces let loose in 1968. It popped into my head back in February, when I was reading a brilliant blog by Newsnight's Paul Mason, titled Twenty reasons why it's kicking off everywhere, which remains among the most incisive analyses of this year's events.

"At the heart of it all are young people, obviously: students; westernised; secularised," he wrote. "... a new sociological type – the graduate with no future ... With access to social media, they can express themselves in a variety of situations ranging from parliamentary democracy to tyranny … They are not prone to traditional and endemic ideologies … They all seem to know each other … I was astonished to find people I had interviewed inside the UCL occupation blogging from Tahrir Square … The common theme is the dissolution of centralised power and the demand for 'autonomy' and personal freedom."

Speaking from an international summit in France, Mason expands on that thought, which he has now poured into a book to be published in January. His travels this year, he explains, have hardened his belief that what ties together 2011's tumultuous events is tangled up with new(ish) means of communication, and a new sense of what it is to be politically organised.

Once you're networked via social media, he says, you're open to profound changes in "who you are and what your personal space is". The idea of any seemingly arbitrary authority standing in the way of all that can easily become an affront – and at the same time, your means of communication offers you a method of opposition and resistance: online, in the real world, or both. This is the essential story of, say, the hundreds of thousands of people who responded to the 2010 death of the young Egyptian Khaled Said by joining the massively influential We are all Khaled Said Facebook group, or the summer's Direct Democracy Now! protests in Athens, said to have been organised solely through social media.

For Mason, all this is also pretty clearly manifested in this year's most iconic archetype: the tent community which springs up in the midst of the city, usually home to the flickering blue light of laptops and the incessant hubbub of intense conversation. "One thing that there has been in common between the Arab spring and the European and American events is this drive – which is almost pathological – to secure space, and live in it," he says. "In one sense, it's a meme … and I think it does satisfy a desire. Once you've lived and experienced this sort of spontaneous, communal, utopian sort of existence online, which is what you do if you're a net-savvy young kid … well, put it this way: if you were to ask yourself, what is the real-world equivalent of being in a 200-strong World Of Warcraft horde [gamespeak for an online community playing the hugely popular fantasy game]? It's probably sitting in a square, in a tent."

And what of all those historical comparisons? Might 2011 be another 1968, or 1989? Mason's favoured comparison is a much more distant year, when abortive revolts spread across Europe at speed, and two fired-up German radicals wrote The Communist Manifesto.

"I think it's going to be seen more in terms of 1848," he says. "1968 was a cultural thing: it only came to street-fighting in Czechoslovakia, the black ghettoes of the US and Paris. In 1989, apart from Romania, there was as much coming from above, through diplomacy, as there was from below. Only in 1848 have we had an explosion that goes from one country to another as fast the mode of communication of the time, and then doesn't stop, and feeds off a zeitgeist that is about freedom, which crosses borders, and involves people identifying with each other from very different cultures."

The dangers ahead

Between 1993 and 1997, Robert Reich served as Bill Clinton's labour secretary. Of late, as if to demonstrate that sections of the US Democrats are being energised and excited by Occupy, from his base at Berkeley University he has visited and spoken at Occupy Oakland (cleared for a second time by the city's police on Monday), Occupy San Francisco, and Occupy Los Angeles. Not without reason, he's wary of too many comparisons with what's happening in the industrialised west and the Arab spring, though he readily accepts that in terms of "political ferment", 2011 may well turn out to be a watershed year.

Reich agrees with the importance Mason places on the new stereotype of the graduate with no future – people, he points out, who now have both solid reasons to protest, and, given the shortage of the kind of jobs that used to fund people through university, plenty of time to do so. In the US and beyond, he says, "the assumption of upward mobility has been brought into serious question"; American opinion polls show that "a plurality of people believes that the game is rigged in favour of people with privilege and power".

What, I wonder, might be the concrete result of all the noise?

"It's impossible to know at this stage. Even in 1968, we had no idea until many years later – and even now, revisionists appear every year, re-interpreting what happened. 1989 was much more clear-cut: we know how the world changed. All we can say about 1968 with any certainty is that there were mass protests and uprisings, people felt nations were moving in the wrong direction, and there was a kind of shock of political recognition among elites, that they had to change direction because of these swelling ranks of discontented people. In the US, that ultimately helped end the Vietnam war – but it also, indirectly, ushered in Richard Nixon, and a Republican, regressive agenda."

Here, he says, lies a danger, common to the US and Europe: that if the mainstream left does not convincingly address the tangle of economic issues that underlies this year's great outbreak of protest and unrest, the initiative could easily be seized by the right. In other words, the onus is on Obama and the Democrats to speak to the moment, and there's an increasing sense that if they don't, the American centre-left may splinter along generational lines. On one side will stand the staid party establishment; on the other, the young networked multitudes, many of whom did their bit for Obama in 2008, but are now gripped by disillusionment that could easily get worse.

For Reich, this possibility has clear echoes of 1968 – and that infamous episode when politicised young people descended on the Democratic convention in Chicago and dramatised the party's miserable failure to rise to the moment, while the city's police used what one convention speaker decried as "gestapo tactics".

"You will recall that in 1968, the Democratic party split," he says. "The establishment Democrats went with [Presidential nominee] Hubert Humphrey, and young people deserted the party. Basically, the Democrats lost big because they didn't know how to respond to the wave. And the drama of 2012 will be a drama, I think, of the Democratic party."

Thirty miles away, Francis Fukuyama is a senior fellow at Stanford University's Center on Democracy, Development and the Rule of Law. His 1992 book The End of History and the Last Man encapsulated the giddy, celebratory mood that followed the European events of 1989, when he claimed, "a remarkable consensus concerning the legitimacy of liberal democracy had emerged throughout the world … as it conquered rival ideologies like hereditary monarchy, fascism, and communism." Comparisons between those times and events in the Arab world now extend into the distance (witness hundreds of online musings about "the Arab 1989"), though when I quiz him about the supposed parallels, he sounds hesitant: Tunisia's young democracy may be hailed as an example of the way ahead, but any such idea founders against the uneasy states of affairs that currently define Egypt and Libya, not to mention the countries where revolts have been met with brutal oppression.

Fukuyama's latest book, The Origins of Political Order, maps the unwieldy period "from prehuman times to the French revolution", and lays out his three prerequisites of stable democratic systems: a functioning state, the rule of law and accountable government – which is a pretty good prism through which to view the Arab spring and its aftermath. "Where the analogy with 1989 breaks down," he says, "is that the historical background in the Arab world is really different from eastern Europe in 1989, and therefore they don't have the same institutional background to make as quick a transition to democracy as Poland and the Czech Republic and Estonia had. The basic impulse is similar, but it's going to take a much longer time for them to get to a real stable set of democratic institutions." In other words, for all the cheering that erupted earlier this year, we could well end up with analogies to, say, Russia and Belarus, rather than Poland and the Czech Republic.

"Yeah … you shouldn't expect miracles. Take a country like Libya: it's not just that they don't have democratic and rule-of-law institutions: they don't even have a state. You've got to construct all these things simultaneously, which is not something Poland had to worry about. So yeah, you may have Islamists in the driving seat, you may have civil war in some cases. It's not going to be an easy task. But you've got to start somewhere."

The west's current big difficulty, he says, is down to "an incipient problem that hasn't really gelled, which is the impact of 30 years of economic growth under a fairly conservative set of economic principles, which in a country like the US has had big distributional impacts – the stagnation of middle class wages and so forth". Even this one-time supporter of Ronald Reagan freely admits that such tensions "will blow up in the system at some point" – but when I mention Occupy and the thousands of networked young politicos who have got involved, he's as sceptical as I expected.

"There's no question that the new social media make it much easier to mobilise people on a short-term basis. But what's missing is a broader set of ideas that govern that mobilisation: that really unite all these people in a sustained and coherent critique of the current system." Fukuyama's style of conversation is too measured to lead him to sneer, but he comes close. "You don't get a broad social movement from a bunch of unhappy kids. You get it from much larger classes of people that have a real social grievance. That class exists, but until they're mobilised in a more effective way, it's not going to have the political impact it ought to."

"You need a coherent leftwing alternative to address a lot of the problems that have accumulated over the last couple of decades," he says. In the absence of anything that meets that description, there will be an opening for what he calls "crazy populism", particularly if "we're headed for a second leg of this recession: continued high unemployment and economic stagnation."

"Just listen to the quality of debate in this country about what the source of the problem is," Fukuyama continues. "It's very dismaying; it just doesn't reflect a real grappling with reality, and the complexity of the issues that face us. And then you've got the right in Europe, which is anti-immigrant, and broadly populist, because they don't like the way elites have governed Europe – and they've got a certain case to be made. That could get a lot stronger in the coming year." As with Reich, his message is: watch out – as any student of history well knows, revolt is often a reliable sign of an imminent backlash from nasty forces of political reaction.

The next 20 years

In 1968, Tariq Ali was a member of the Trotskyist International Marxist Group, up to his neck in protest against the Vietnam War, and in regular contact with the young enragés who were making the political weather in Paris. The week before we speak, he was at Occupy Oakland; he has also visited Occupy London. "Oh, you know … It's very sweet. It's lovely seeing young people being engaged again. I'm not being patronising, I think it's great. But I think you have to recognise it for what it is: essentially, a symbolic protest.

"The most striking feature of these uprisings," he goes on, "is that nobody has yet demanded a totally alternative social and economic programme – apart from Greece, but even they are in a confused state: they say no to austerity, but there isn't even a charter of six or eight demands. And if they carry on thinking like that, they will be defeated. Without any doubt. It's a huge weakness."

What he says points up the clash between what you might think of as the Old New Left, and the generation that has recently taken centre-stage. Others might rhapsodise about autonomous communes and the glories of non-hierarchical organisation: by contrast, though their politics are light years apart, Ali echoes Fukuyama's argument that without a coherent programme and convincing mass support, you're toast. So is there reason for even the most qualified optimism?

"Yes. Because I think these are the first signs – not of a unified movement, but of different movements in different countries that are searching for something. And that process of searching is extremely important. We're in a period of transition."

And when might things start to cohere? "I would have thought it depends a great deal on how the economic system functions over the next 20 years. I think the next two decades will be quite decisive."

His words reflect those of just about everyone I've spoken to over the last six weeks, whether they've been camped in city squares, or cloistered in university rooms. All the historical comparisons go some way to illuminating our own times, but if you get too hooked on 1968 or 1989, you're in danger of underestimating one sobering fact: that we're in the midst not just of an unbelievably volatile and unpredictable year, but a volatile and unpredictable era, in which this year's events are likely to only be the start. Hold on tight.